#define _CRT_SECURE_NO_WARNINGS 1

#include<iostream>
using namespace std;

class A 
{
public:
	int _a;
};

class B: virtual public A
{
public:
	int _b;
};

class C : virtual public A
{
public:
	int _c;
};

class D :public B, public C
{
public:
	int _d;
};

int main()
{
	D d;
	A a;
	B b;
	C c;
	d._a = 1;
	d._b = 2;
	d._c = 3;
	d._d = 4;
	b._a = 100;

	return 0;
}